P0748 on 2002-2013 Chevrolet Avalanche — Pressure Control Solenoid "A" Electrical
1 vehicles · 1 makes · $1,500-$3,500 repair
Most Reported On
P0748 is an OBD-II diagnostic trouble code meaning “Pressure Control Solenoid "A" Electrical.” P0748 is a generic powertrain code meaning the transmission control module has detected an electrical fault — voltage or resistance out of the expected range — in the circuit for pressure control solenoid "A". This solenoid regulates hydraulic line pressure inside an automatic transmission, adjusting how firmly the clutches and bands apply based on speed, load, and throttle position. When the computer can't control the solenoid electrically, the transmission often defaults to maximum line pressure or limp mode, so you may feel harsh or erratic shifts, slipping, delayed engagement when shifting into Drive, or being locked into a single gear. Because it is an electrical-circuit code, the fault is usually in the solenoid itself or its wiring rather than a purely hydraulic problem, though contaminated fluid can damage the solenoid. Continuing to drive with slipping and overpressure shifts can overheat the transmission and lead to expensive internal damage, so this should be repaired promptly. This code is most commonly reported on 2002-2013 Chevrolet Avalanche, with repair costs ranging from $1,500 to $3,500.
Common Causes
Typical Repair Cost
Based on 1 documented vehicle-specific issues. Actual cost depends on root cause and vehicle.
Diagnostic Tools
To diagnose P0748, you'll need an OBD-II scanner. Here are our recommendations at every price point.
ANCEL AD310 Classic OBD-II Scanner
by ANCEL
A simple, affordable code reader that reads and clears check engine codes. Great for quick diagnostics on any OBD-II vehicle (1996+).
- Read & clear engine codes
- View freeze frame data
- I/M readiness status
- No batteries or app needed
BlueDriver Pro Bluetooth Scanner
by BlueDriver
Bluetooth OBD-II scanner with a free companion app. Provides enhanced diagnostics, smog readiness, and repair reports sourced from a database of verified fixes.
- Enhanced diagnostics (ABS, SRS, transmission)
- Repair Reports with verified fixes
- Smog check readiness
- Free app (iOS & Android)
LAUNCH CRP123X OBD-II Scanner
by LAUNCH
A professional-grade handheld scanner that reads all four major systems (engine, transmission, ABS, SRS) with live data streaming and graphing.
- Engine, transmission, ABS, SRS diagnostics
- Live data stream & graphing
- AutoVIN for vehicle identification
- Free lifetime updates via Wi-Fi
Autel MaxiCOM MK808S Diagnostic Tool
by Autel
Shop-level diagnostic tablet with bi-directional control, active tests, and full system coverage. Ideal for serious DIYers and small shops.
- All-system diagnostics (25+ modules)
- Bi-directional control & active tests
- Oil reset, EPB, BMS, TPMS, injector coding
- 7-inch touchscreen with Android OS
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FAQ
What does P0748 mean?
P0748 stands for "Pressure Control Solenoid "A" Electrical." P0748 is a generic powertrain code meaning the transmission control module has detected an electrical fault — voltage or resistance out of the expected range — in the circuit for pressure control solenoid "A". This solenoid regulates hydraulic line pressure inside an automatic transmission, adjusting how firmly the clutches and bands apply based on speed, load, and throttle position. When the computer can't control the solenoid electrically, the transmission often defaults to maximum line pressure or limp mode, so you may feel harsh or erratic shifts, slipping, delayed engagement when shifting into Drive, or being locked into a single gear. Because it is an electrical-circuit code, the fault is usually in the solenoid itself or its wiring rather than a purely hydraulic problem, though contaminated fluid can damage the solenoid. Continuing to drive with slipping and overpressure shifts can overheat the transmission and lead to expensive internal damage, so this should be repaired promptly.
What are the most common causes of P0748?
The most common causes of P0748 are: Failed pressure control solenoid A (open or shorted solenoid windings), Damaged, frayed, or shorted wiring in the solenoid circuit, including the transmission case connector, Corroded or loose electrical connectors at the transmission harness, Low, dirty, or contaminated transmission fluid degrading or sticking the solenoid, Clogged transmission filter or debris in the valve body hydraulic passages, Faulty transmission control module or PCM driver circuit (rare). The specific cause varies by vehicle.
How much does it cost to fix P0748?
Repair costs for P0748 range from $1,500 to $3,500, depending on the vehicle and root cause.
Which vehicles are affected by P0748?
Au7o has documented P0748 across 1 vehicle models from 1 manufacturers: Chevrolet.
Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.